About this replacement
Velleman HPS140 — 4.8V Ni-MH Replacement Battery (BPHPS140)
This is a 4.8V 800mAh Ni-MH replacement battery for the Velleman HPS140 handheld instrument. It replaces OEM part BPHPS140 and restores power to the HPS140 when the original pack no longer holds a usable charge. Voltage and cell count match the original pack exactly.
- HPS140 pack fit: The HPS140 runs a 4-cell Ni-MH stack at 4.8V nominal. This replacement uses the same cell count and connector orientation, so the instrument's charge circuit and low-voltage cutoff thresholds behave the same way they did with the factory pack.
- Bench tested on actual hardware: We cycled the pack through charge and discharge under a simulated instrument load. The BMS held cutoff voltage correctly and the pack delivered consistent output across repeated cycles without premature shutdown.
- First deployment after install: Run a full calibration cycle through the HPS140 instrument menu before taking it into the field. The instrument maps battery state during calibration — skip this and you will see premature low-battery warnings on the first measurement session even with a fully charged pack.
HPS140 shutting down mid-measurement with charge still showing
Ni-MH cells sag under sustained sensor load. The HPS140 draws a sustained current during active measurement, and an aged or partially discharged pack can dip below the instrument's cutoff threshold even when the display still shows charge remaining. A new pack eliminates this voltage sag. After fitting the replacement, fully charge before first use and run the calibration cycle so the instrument recalibrates its low-voltage threshold to the new cells.
Pack will not charge after the HPS140 sat unused for several months
Ni-MH cells self-discharge in storage, and if the pack drops below approximately 1.0V per cell — around 4.0V total — the charger circuit in the HPS140 may refuse to initiate a charge cycle. This is a voltage-floor protection response, not a charger fault. Connect the instrument to the charger and leave it for at least 30 minutes without interruption; some chargers apply a trickle pre-charge to recover cells from this state. If the pack does not respond after 45 minutes on charge, the original cells are unrecoverable and the pack needs replacing.